PHOSPHATIC MANURES.

Waikato Times, Volume 112, Issue 18808, 2 December 1932, Page 12

PHOSPHATIC MANURES.

EFFECTS ON GfiOWTH. Phosphales. unliUo 111-' nilrnsciwus fertilisers. increase the propor!ion of clover in ‘.lie herbage, and so add greatly to its protein ron’enl. 7 Ins Increase is not routined to the spring months, as happens with nitrogenous fertilisers: it is maintained through the season, and is continued in the next. The gain in protein may lie considerable —much greater than the gain in dry matter. In (tie tlrst year after application water soluble phosphate is most effective, so that superphosphate comes out best. Citric soluble phosphate comes next, hence high ■soluble basic slag Is second. .Mineral phosphate and low soluble basic slag are less effer five.

The value of mineral phosphate as compared with the* others changes a good deal according to soil and season. In Ihe drier conditions of Hertfordshire and tin* Kdslern counties, under investigation by the Itothamsted Experimental station, it came a long way behind high soluble slag and was very similar to low soluble slag: hi the Minister, warmer renditions of Devonshire it acted more like high soluble slap and was much superior to the low soluble slag. In the second year the high soluble basic slag did better than superphosphate at several of the centres, both on Ihe bay land and mi the grass repeatedly mown, though it had not hern caught up with superphosphate. A! the I levmistiire eenire mineral phosphate aeted as well a- high soluble slag, though it w.i . -.till behind on Ihe two .'ears' programme, hut the low soluble slag: showed no sign of improvement. The experiment is being eontinued b> I lie I to! ha m>l erl aid b oril ies to see wiial happens in the third and fourth years.